Pressurized fluid delivery system and method of use

ABSTRACT

A pressurized fluid delivery system and method that can be used to interrogate objects, such as the interrogation and detonation of IEDs. The system and method entail pressurizing a liquid within a vessel with a compressed gas source so that the liquid within the vessel is at a pressure above atmospheric pressure. The pressurized liquid, the compressed gas, or a mixture thereof is then selectively delivered to an outlet, and then discharged from the outlet to physically interrogate the object.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.61/416,004, filed Nov. 22, 2010, the contents of which are incorporatedherein by reference.

BACKGROUND OF THE INVENTION

The present invention generally relates to systems and methods that makeuse of pressurized gases and liquids. More particularly, the presentinvention relates to pressurized fluid delivery systems and methods thatuse pressurized fluid to physically interrogate objects, a particularlynotable example of which are buried improvised explosive devices (IEDs).

Improvised explosive devices (IED) are explosive devices that aretypically constructed of scavenged components and used foranti-personnel and anti-vehicle activities. Because of their makeshiftconstruction, IEDs can vary widely in their size, shape and detonationsystem. As such, IEDs can be configured to be detonated by an electricalsignal or as a result of being subjected to vibration or force. Varioustechniques have been proposed to disrupt IEDs, including electronicjamming systems, high voltage discharges, lasers, projectiles, kineticenergy vibrations, water jets, and mechanical arms and rollers.Mine-protected vehicles (MPVs) have been developed to protect personnel,as well as serve as vehicles specifically adapted to disrupt IEDs. Aparticular example is the BUFFALO®, which is a type of mine-resistantambush protected (MRAP) vehicle built by Force Protection, Inc. Inaddition to being capable of withstanding bomb blasts, the BUFFALO® isequipped with a robotic arm or crane that can be used to examine andremove IEDs.

While the various techniques that have been used to disrupt IEDs haveproven to be generally effective, further improvements are stilldesired. One such example relates to the use of water to interrogateIEDs. When used for this purpose, the effectiveness of a water jetdepends on its velocity and volumetric flow rate. However, the flowoutputs of typical centrifugal-type water pumps decrease significantlyas the output pressure increases. Though constant displacement pumps canbe configured to have both high output flow rates and pressures, theyare limited to a single output flow rate at a single output pressure,which significantly limits the versatility of the water jet whenattempting to excavate and interrogate an IED.

BRIEF DESCRIPTION OF THE INVENTION

The present invention provides a pressurized fluid delivery system andmethod that can be used to interrogate objects, such as theinterrogation and detonation of IEDs, and has multiple operating modesin which a gas and/or liquid may be used as the interrogation media.

According to a first aspect of the invention, the pressurized fluiddelivery system includes a vessel configured to contain a fluid underpressure. A liquid source is fluidically connected to the vessel forsupplying a liquid to the vessel. A compressed gas source is alsofluidically connected to the vessel and is adapted to supply acompressed gas to the vessel and pressurize the liquid within the vesselto a pressure above atmospheric pressure. An outlet is fluidicallyconnected to the vessel and is separately fluidically connected to thecompressed gas source. A first valve means controls the flow of theliquid from the vessel to the outlet, a second valve means controls theflow of the compressed gas from the compressed gas source to the outlet,and a third valve means controls the flow of the compressed gas from thecompressed gas source to the vessel. The first and second valve meansare adapted to be operated to selectively deliver the liquid, thecompressed gas, or a mixture thereof to the outlet.

Another aspect of the invention is method of using a pressurized fluiddelivery system comprising the elements described above to physicallyinterrogate an object. Such a method includes delivering the liquid fromthe liquid source to the vessel, delivering the compressed gas from thecompressed gas source to the vessel to thereby pressurize the liquidwithin the vessel to a pressure above atmospheric pressure, operatingthe first and second valve means to selectively deliver the liquid, thecompressed gas, or a mixture thereof to the outlet, and then dischargingthe liquid, the compressed gas, or the mixture thereof from the outletto physically interrogate the object.

According to another aspect of the invention, a method of usingpressurized fluid to physically interrogate an object includespressurizing a liquid within a vessel with a compressed gas source sothat the liquid within the vessel is at a pressure above atmosphericpressure, selectively delivering the pressurized liquid, the compressedgas, or a mixture thereof to an outlet, and then discharging thepressurized liquid, the compressed gas, or a mixture thereof from theoutlet to physically interrogate the object with the pressurized liquid,the compressed gas, or the mixture thereof.

A technical effect of the invention is the ability to selectively use apressurized liquid, a compressed gas, or a mixture thereof as theexcavation media for physically interrogating a buried object, such asan IED. A pressurized liquid (such as water) is beneficial for softeningand penetrating hard dry soil, and is also effective for buoying andjetting away the softened soil from around a buried object. Thereafter,the system can switch to using the compressed gas or liquid-gas mixtureas the excavation media to blow the liquid that has accumulated withinthe excavated hole.

Other aspects and advantages of this invention will be betterappreciated from the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 2 schematically represent all-fluid and all-pneumaticoperating modes, respectively, for a pressurized fluid delivery systemin accordance with an embodiment of this invention.

FIG. 3 schematically represent a pressurized liquid-gas delivery systemin accordance with a preferred embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 1 and 2 schematically represent two operating modes of apressurized fluid delivery system 10 of the present invention. In FIG.1, an all-fluid operating mode is represented, meaning that the fluiddelivered by the system 10 does not intentionally contain any gasses.FIG. 2 represents an all-gas operating mode, meaning that the fluiddelivered by the system 10 does not intentionally contain any liquids.As will become apparent from the following discussion, another possibleoperating mode involves the delivery of both liquid and gas.

FIGS. 1 and 2 represent the fluid delivery system 10 as including apressure vessel 12 filled with a liquid 14, a nonlimiting example ofwhich is water. The vessel 12 includes an inlet through which the liquid14 enters the vessel 12 from a suitable source 16, and a liquid outletline 18 connected to a valve 20, through which the liquid 14 is able toexit the vessel 12 and flow into a system outlet 22 before arriving atits intended use 24. The system 10 is further shown as including acompressed gas source 26 connected to the vessel 12 with a gas inletline 28 through which a compressed gas 30 enters the vessel 12 topressurize its contents at a pressure above atmospheric pressure. Thegas inlet line 28 is also connected by a gas by pass line 32 to a valve34, through which the gas 30 is able to flow into the system outlet 22before arriving at its intended use 24. Other components that might beconventionally included in a pressurized fluid system, for example,pressure relief valves and pressure regulators, are not shown but can beincorporated into the system 10 in any suitable manner known in the art.

According to a preferred aspect of the invention, the compressed gassource 26 continuously supplies the vessel 12 with the compressed gas30, so that the source 26 compensates for any pressure drop that wouldresult from the discharge of a quantity of the liquid 14 from the vessel12, so that the contents of the vessel 12 are continuously maintained ata desired pressure. The compressed gas source 26 is also preferablycapable of continuously supplying the compressed gas 30 to the gas inletline 28 and gas bypass line 32 so that any drop in pressure that wouldresult from a quantity of the gas 30 being discharged from the bypassline through the system outlet 22 will be compensated for. Because thepressure within the vessel 12 is dependent on the pressure of thecompressed gas 30, the pressure of the pressurized liquid 14 within thevessel 12 and at the valve 20 and the pressure of the compressed gas 30within the gas bypass line 32 and at the valve 34 can be the very same(absent any devices for reducing pressures).

The valves 20 and 34 are preferably controlled with a suitable controlsystem (not shown) to enable the pressurized liquid 14 (FIG. 1) orcompressed gas 30 (FIG. 2) to be discharged from the system 10 at acontrolled rate through the system outlet 22. Because the pressures ofliquid 14 and gas 30 can be the very same at the valves 20 and 34, thevalves 20 and 34 can also be controlled to deliver the liquid 14 and gas30 to the system outlet 22 in amounts that will produce a desiredliquid-gas mixture (for example, a mist).

The pressurized fluid delivery system 10 represented in FIGS. 1 and 2can be used to deliver the pressurized liquid 14 and/or compressed gas30 for a wide variety of intended uses 24. As nonlimiting examples, thesystem 10 can be used in fire fighting applications, compressed air foamsystem delivery and installation applications, irrigation systems, washdown equipment, decontamination applications, and IED interrogation. Inthe case of IED interrogation, the valves 20 and 34 can be controlled toenable the system 10 to use air (and/or another suitable gas), water(and/or another suitable liquid), and mixtures thereof (for example, amist) as excavation media. The ability to use any combination ofcompressed gas 30 and pressurized liquid 14 increases the versatility ofexcavation applications. The system 10 is well suited for mobileapplications in which compressed air is available, such as on utility,service, emergency and military vehicles equipped with on-board aircompressors that may be powered by, for example, a power takeoff (PTO)shaft driven by the engine of the vehicle. As with other fluid systemsthat deliver and contain a fluid at a high pressure or flow rate, theoutputs of such air compressors are often regulated at a prescribedlevel deemed safe and appropriate for the intended use of the compressedair. The system 10 of this invention is able to utilize a continuoussupply of compressed air from an air compressor (source 26) topressurize the contents of the vessel 12, so that the compressed air 30is able to force the contents of the vessel 12 into the liquid outletline 18 of the vessel 12. In the case of a PTO-powered air compressor,the air compressor begins to build air pressure when a user activatesthe PTO on the vehicle while a valve 36 is closed. By opening the valve36, the user is able to activate the system 10 and build pressure withinin the vessel 12.

As previously noted, a technical effect of the system 10 is the abilityto selectively use the pressurized liquid 14, the compressed gas 30, ora mixture thereof as the excavation media for physically interrogating aburied object, such as an IED. The ability to switch between thepressurized liquid 14 and compressed gas 30 allows a user to firstemploy the pressurized liquid 14 to soften and penetrate a hard dry soiland then buoy and jet away the softened soil from around a buriedobject. The system 10 can then be switched to use the compressed gas 30or a liquid-gas mixture as the excavation media to blow the liquid 14that has accumulated within the excavated hole. In addition to thisoperational benefit of being able to selectively use the pressurizedliquid 14 and/or compressed gas 30, the system 10 also benefits from themanner in which the compressed gas 30 is used to pressurize the liquid14 within the vessel 12. The effectiveness of the liquid 14 whenexcavating a buried object is dependent on the velocity and volumetricflow rate of the liquid 14. For example, when discharged intoatmospheric conditions, the velocity and flow rate of water at apressure of about 175 psig (about 12 bar) are about 50% greater thanwater at a pressure of about 75 psig (about 5 bar), thus generallyincreasing the excavation effectiveness by about 50%. For typicalcentrifugal type water pumps, water flow output decreases significantlyas pressure rises, thus limiting their ability to continuously deliverwater at an adequate pressure and flow rate for interrogation andexcavation purposes. In contrast, in the system 10 represented in FIGS.1 and 2, as the pressure within the vessel 12 is increased, dischargeflow of the liquid 14 from the vessel 12 also increases as long as thecapacity of the compressed gas source 26 to deliver compressed gas 30 tothe vessel 12 is greater than the capacity of the vessel 12 to deliverthe liquid 14 to the output 22. In addition, whereas constantdisplacement pumps operate to have a single output flow rate andpressure, the pressure of the compressed gas 30 deceived to the vessel12 can be readily changed to change the pressure and flow rate of theliquid 14 from the vessel 12.

FIG. 3 schematically represents a particular embodiment of thepressurized fluid delivery system 10 of FIGS. 1 and 2, and isrepresented as being implemented with additional components for use asan IED interrogator. The various components of the system 10 aresummarized below.

Air for use as the compressed gas 30 of the system 10 is drawn through afilter 38, for example, a single-stage filter designed to remove dirtand debris from air prior to its entry into a compressor unit,corresponding to the compressed gas source 26 in FIGS. 1 and 2. Thecompressor unit 26 can make use of various types of compressors, forexample, a single-stage, positive-displacement, oil-flooded, rotaryscrew type design, in which case the output of the compressor unit 26 isa mixture of pressurized air and oil. As is generally known in the art,the compressor unit 26 may further comprise a check valve (not shown)that prevents the air/oil mixture from flowing backward to pressureregulators during shutdown, and an inlet valve (not shown) thatmodulates the amount of air compressed by the compressor unit 26.

The compressor unit 26 is connected to a receiver tank 40 via adischarge hose 42. The receiver tank 40 receives the pressurized air/oilmixture from the compressor unit 26, and allows the bulk of the oilwithin the mixture to drop out, after which finer oil particles areseparated from the compressed air, for example, using an internalcoalescing element 44 of a type known in the art. The receiver tank 40then recycles oil to an oil cooler unit 46 through an oil line 48 thatincludes an oil filter 50. The oil cooler unit 46 preferably includes anair-to-oil heat exchanger that maintains the oil within a desiredtemperature range. The cooled oil is then returned to the air compressorunit 26 via an oil return line 52. A scavenger hose 53 allows air andoil accumulated by the coalescing element 44 of the receiver tank 40 toflow to the vacuum side of the compressor unit 26.

From the receiver tank 40, the resulting compressed air 30 passesthrough an air line 54 to a minimum pressure valve/blowdown valveassembly 56, which in preferred embodiments of the invention comprises aminimum pressure valve 58 plumbed to a blowdown valve 60. The minimumpressure valve 58 is configured to ensure that a minimum upstreampressure is maintained before air is allowed to pass downstream. Whenthe system 10 is shut down, the blowdown valve 60 relieves the pressurein the system 10 upstream of the minimum pressure valve 58. Air pressurefrom the compressor unit 26 is transmitted through a blowdown pilot hose62 to the pilot side of the blowdown valve 60, which upon shutdown ofthe system 10 opens the valve 60 to relieve pressure from the system 10by allowing air to blow out of an orifice on the valve 60.

As seen in FIG. 3, the minimum pressure valve/blowdown valve assembly 56is also connected with an air hose to a dual pressure regulator assembly78, which sets the maximum operating pressure for the compressed gas 30within the system 10. The regulator assembly 78 functions to allow airpressure to pass downstream when a given pressure is reached, and ispreferably adjustable to pass air at different pressures, for example,100 psig and 175 psig (about 7 to about 12 bar). The regulator assembly78 may include one or more pressure regulators, in which case theregulators are connected through a solenoid valve (not shown) thatdetermines which of the individual pressure regulators is used. FIG. 3represents the situation in which the regulator assembly 78 includes tworegulators whose outputs are connected through separate air hoses 80 and82 to the compressor unit 26 for the purpose of setting the maximumoperating pressure for the compressed gas 30 within the system 10 bypneumatically modulating the flow of air through the inlet valve tocompressor of the compressor unit 26.

The minimum pressure valve/blowdown valve assembly 56 is furtherconnected with an air line 57 to a pilot valve and solenoid valveassembly 64, which serves as an adjustable pressure regulator for thecompressed gas 30 delivered to the vessel 12. The pilot valve andsolenoid valve assembly 64 preferably includes a piloted regulatorvalve, a solenoid valve, and piping that connects the two. In preferredembodiments of the system 10, the pilot valve is a 1:1 piloted regulatorvalve, and the pressure supplied to the pilot port of the pilot valve isthe same pressure that the valve allows to pass downstream. The pilotvalve and solenoid valve assembly 64 is connected by a hose 66 to acheck valve 68 that is located downstream of the assembly 64 to preventbackward flow from a hose reel unit (corresponding to the system outlet22 in FIGS. 1 and 2), through which the interrogation media(corresponding to the pressurized liquid 14 and/or compressed air 30)flows during an interrogation operation performed by the system 10. Inthe case of a vehicle equipped with an extendable robotic arm or crane70, for example, of a type provided on the BUFFALO® MRAP previouslydiscussed, the hose reel unit 22 allows a hose 72 to be extended fromand retracted onto a hose reel 74, depending on the deployment of thecrane 70. As represented in FIG. 3, the hose 72 terminates with a nozzle76, which may be of a specially designed type that has specific holes ororifices to generate a stream of water and/or air that is conducive toIED excavation.

An instrument panel assembly 84 is connected via a hose 86 to thecompressed air within the receiver tank 40. The panel assembly 84preferably includes a pressure switch-gauge, a temperature switch-gauge,and a reset switch. The pressure switch-gauge monitors pressure withinthe receiver tank 40, and also acts as an over-pressure switch thatshuts down the system 10 in the event that the pressure rises above apredetermined level. The temperature switch-gauge monitors the oiltemperature within the receiver tank 40 and also acts as anover-temperature switch that shuts down the system 10 in the event thatthe oil temperature rises above a predetermined level. The reset switchcan be a spring-latched pushbutton that can be reset in the event thatan over-pressure or over-temperature shutdown condition occurs. In FIG.3, the same hose 86 that connects the receiver tank 40 to the panelassembly 84 also connects the receiver tank 40 to an electronic pressureregulator 88 that controls air pressure delivered to the pilot valve andsolenoid valve assembly 64.

The line 57 that connects the minimum pressure valve/blowdown valveassembly 56 to the pilot valve and solenoid valve assembly 64 is shownin FIG. 3 as branching off to define another air line 59 that connectsthe minimum pressure valve/blowdown valve assembly 56 to a manifoldblock assembly 90 via a check valve 92. The manifold block assembly 90is configured to control the flow of air, water, or an air-water mixture(mist) to the hose reel unit 22 and its nozzle 76. The manifold blockassembly 90 is represented as including three valves, corresponding tothe three valves 20, 34 and 36 of FIGS. 1 and 2. The valve 36 is anormally-closed two-way solenoid valve that allows the flow ofcompressed air from the compressor unit 26, through a hose(corresponding to the inlet line 28 in FIGS. 1 and 2), and into thevessel 12. The valve 20 is also a normally-closed two-way solenoidvalve, and allows pressurized water to flow from the vessel 12 through afirst hose (corresponding to the outlet line 18 in FIGS. 1 and 2), andthen through a second hose (corresponding to the system outlet 22 inFIGS. 1 and 2) to the hose reel unit 22 and its nozzle 76. Finally, thevalve 34 is a normally-open two-way solenoid valve that allowspressurized air to flow through a hose (corresponding to the bypass line32 in FIGS. 1 and 2) and then through the system outlet 22 to the hosereel unit 22 and its nozzle 76. The normally-closed valve 36 isactivated when a main switch (not shown) located on the instrument panel84 is ON. The normally-closed valve 20 allows pressurized water to flowto the hose reel unit 22 and its nozzle 76 when a water-mode switch (notshown) located on the instrument panel 84 is ON. Finally, thenormally-open valve 34 allows compressed air to flow to the hose reelunit 22 and its nozzle 76 when an air-mode switch (not shown) located onthe instrument panel 84 is ON.

FIG. 3 represents an alternative to the connection between the minimumpressure valve/blowdown valve assembly 56 and the manifold blockassembly 90. The alternative is represented as an air line 59 a thatconnects the manifold block assembly 90 to the output of the pilot valveand solenoid valve assembly 64, instead of the manifold block assembly90 being directly connected to the minimum pressure valve/blowdown valveassembly 56. With this variation, the vessel 12 is pressurizeddownstream of the valve assembly 64 through the line 59 a, instead ofupstream of the valve assembly 64 through the air line 59. With thisvariation, pressure in the vessel 12 can be adjusted with the valveassembly 64, providing a simple method for adjusting the pressure andflow of the liquid 14 to the hose reel unit 22. Such a capability wouldbe particularly useful if, for example, the pressure within the vessel12 and/or the flow rate of the liquid 14 were excessive for the intendeduse, for example, excavation of an IUD, in which case the valve assembly64 can be used to reduce the pressure within the vessel 12 andpotentially provide better control the flow rate and velocity of theliquid discharged through the hose reel unit 22.

The system 10 is also represented in FIG. 3 as including two electricball valves 94 and 96 whose operations are controlled by a refill-modeswitch (not shown) located on the instrument panel 84. The first ballvalve 94 is connected to the manifold block assembly 90 and, whenactivated, allows water introduced into the system 10 by the hose reelunit 22 (which therefore is also capable of serving as the liquid source16 in FIGS. 1 and 2) to flow through the manifold block assembly 90 andthen to the vessel 12 during the refill mode. The second ball valve 96is located on the vessel 12 and serves as a vent for the vessel 12 torelieve pressure during the refill mode. Other means for refilling thevessel 12 are foreseeable, including manually-activated ball valves andauxiliary connections to a water pump.

Finally, there is preferably a provision to bypass the system 10 in theevent that the vessel 12 ruptures or otherwise cannot hold pressure. Byselecting “Bypass” mode with the instrument panel 84, the manifold blockassembly 90 is closed and the solenoid valve of the pilot valve andsolenoid assembly 64 opens, allowing air to bypass the manifold blockassembly 90 and exit the system through the hose reel unit 22.

While the invention has been described in terms of specific embodiments,it is apparent that other forms could be adopted by one skilled in theart. For example, the physical configuration of the system 10 coulddiffer from that shown, and various components other than those notedcould be used. Therefore, the scope of the invention is to be limitedonly by the following claims.

The invention claimed is:
 1. A pressurized fluid delivery system adaptedto use pressurized fluid to physically interrogate an object, the systemcomprising: a vessel configured to contain a fluid under pressure; aliquid source fluidically connected to the vessel for supplying a liquidto the vessel; a compressed gas source fluidically connected to thevessel and adapted to supply a compressed gas to the vessel andpressurize the liquid within the vessel to a pressure above atmosphericpressure; an outlet fluidically connected to the vessel and separatelyfluidically connected to the compressed gas source; a first valve meansfor controlling flow of the liquid from the vessel to the outlet; asecond valve means for controlling flow of the compressed gas from thecompressed gas source to the outlet; a third valve means for controllingflow of the compressed gas from the compressed gas source to the vessel;and means for operating the first and second valve means to selectivelydeliver the liquid, the compressed gas, or a mixture thereof to theoutlet.
 2. The pressurized fluid delivery system according to claim 1,wherein the outlet comprises a hose and nozzle.
 3. The pressurized fluiddelivery system according to claim 2, wherein the outlet is coupled toan extendable crane.
 4. The pressurized fluid delivery system accordingto claim 3, wherein the extendable crane is coupled to a vehicle onwhich the pressurized fluid delivery system is mounted.
 5. Thepressurized fluid delivery system according to claim 1, wherein thecompressed gas source is adapted to continuously supply the vessel withthe compressed gas so as to compensate for any pressure drop that wouldresult from the delivery of the liquid to the outlet so that the liquidwithin the vessel is continuously maintained at the pressure aboveatmospheric pressure.
 6. The pressurized fluid delivery system accordingto claim 1, wherein the compressed gas and the liquid within the vesselare at the same pressure above atmospheric pressure.
 7. A pressurizedfluid delivery method of using the pressurized fluid delivery system ofclaim 1 to physically interrogate an object, the method comprising:delivering the liquid from the liquid source to the vessel; deliveringthe compressed gas from the compressed gas source to the vessel tothereby pressurize the liquid within the vessel to a pressure aboveatmospheric pressure; operating the first and second valve means toselectively deliver the liquid, the compressed gas, or a mixture thereofto the outlet; and discharging the liquid, the compressed gas, or themixture thereof from the outlet to physically interrogate the object. 8.The pressurized fluid delivery method according to claim 7, wherein thefirst and second valve means are operated to selectively deliver onlythe liquid to the outlet and discharge only the liquid from the outletto physically interrogate the object.
 9. The pressurized fluid deliverymethod according to claim 7, wherein the first and second valve meansare operated to selectively deliver only the compressed gas to theoutlet and discharge only the compressed gas from the outlet tophysically interrogate the object.
 10. The pressurized fluid deliverymethod according to claim 7, wherein the first and second valve meansare operated to selectively deliver the mixture of the liquid and thecompressed gas to the outlet and discharge the mixture from the outletto physically interrogate the object.
 11. The pressurized fluid deliverymethod according to claim 10, wherein the mixture is a mist.
 12. Thepressurized fluid delivery method according to claim 7, wherein theobject is a buried improvised explosive device.